Dirt separator for a vacuum cleaner

A dirt separator (10, fig 3) for a vacuum cleaner, the dirt separator comprises a chamber (36, fig 3) having an inlet (21, fig 3) through which dirt-laden fluid enters the chamber (36, fig 3) and an outlet (38, fig 3) through which cleansed fluid exits the chamber (36, fig 3) and a disc 40 located at the outlet (38, fig 3), the disc 40 being arranged to rotate about a rotational axis (48, fig 3) and comprising holes 47 through which the cleansed fluid passes. When viewed along the radial direction of the disc, the path of each hole 47 through the thickness of the disc defines a centerline 70, the centerline 70 being inclined such that it is non-perpendicular to the disc 40. The centerline 70 of each hole 47 is inclined such that it intersects the upstream face of the disc 40 at a point which is behind, in the direction of rotation of the disc 40, the point at which the centerline 70 intersects the downstream face of the disc 40.